Automatic air-brake system.



. MILLER.

AUTOMATIC AIB BRAKE SYSTEM.

. APPLICATION FILED NOV. 7, 1913.

Patented July 21, 1914.

THE NORRIS PETERS 50.. PHOTO-LITHOV. wAsuuvumu n l WILLIAM MILLER, OFGILMAN, MONTANA.

AUTOMATIC AIR-BRAKE SYSTEM.

Application filed November 7, 1913.

Specification of Letters Patent.

Patented July 21, 1914.

Serial No. 799,773.

To all whom it may concern:

Be it known that I, WILLIAM MILLER, a citizen of the United States,residing at Gilman, in the county of Lewis and Clark and State ofMontana, have invented certain new and useful Improvements in AutomaticAir-Brake Systems; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it-appertains to make and use thesame.

This invention comprehends improvements in airbrake systems for use inconnection with vehicles, such as trolley and railway cars, and relatesmore particularly to such a system as will automatically operate to stopa train when a predetermined speed has been reached.

One of the objects of the invention is to provide in a system of thisnature a brake cylinder into which air is continually forced byatraction operated pump, the pressure within the brake cylinder beingdependent upon the speed at which the vehicle is traveling and thiscylinder being provided with a discharge valve which will automaticallyclose when the train is traveling at such a speed as to produce apredetermined pressure within the cylinder.

Another object of the invention is to provide in an airbrake system ofthis nature,

means whereby the brakes may be applied at any time by manually closingan air valve.

With these and other objects in view as willbecome more apparent as thedescription proceeds, the invention consists in certain novel featuresof construction, combination and arrangement of parts as will behereinafter more fully described and claimed.

For a complete understanding of my in vention, reference is to be had tothe following description and accompanying drawings, in which- Figure 1is a vertical longitudinal sectional view through a car, showinginelevation my improved airbrake system applied thereto, Fig. 2 is avertical longitudinal sectional view, partly in elevation showing theconstruction of the pump and brake cylinder, and Fig. 3 is a fragmentarydetail sectional view, showing the automatically operated valve whichcloses the discharge from the brake cylinder, whereby the brakes areapplied.

Referring in detail to the drawings by numerals, 5 designates, as anentirety, a car body and 6 designates the supporting wheels for the car.

In carrying out my invention, I provide a brake cylinder 7, having twodischarge ports 8 and 9 formed in one end thereof and being alsoprovided with an intake port 10 through which air is forced from a pump11. shown in Fig. 2, the pump is of the double acting type, having apair of intake ports 12 other and that the manner in which they aresupported upon the car is immaterial. In

the present instance I have shown the pump positioned above the brakecylinder and It will be understood that the straps 16 surrounding thebrake cylinder,

whereby the latter is secured to the bottom of the car 5.

The piston 17 of the pump is operated by means of a connecting rod orpitman'18 connected atone end to the crosshead 19 and at its other endto a friction wheel 20 carried upon the inner end of a lever 21.

The friction wheel 20 is adapted to engage a similar wheel or disk 22which is secured to the rotatable axle 23; In order that the wheel 20may be thrown into engagement with the wheel or disk 22, or held fromengagement therewith, I provide a vertical rod 24 having a hand wheel 25secured to its upper end and being connected at its lower end to, theforward or outer end of the lever 21. This rod is threaded intermediateits ends, as indicated by the numeral 26 and the threaded portion worksthrough a sleeve or nut 27 rigidly securedin the floor of the car,

so it will be apparent that a rotation'of the rod 24 will either raiseor lower the wheel 20. When the two friction wheels are engaged and thecar is in motion, the piston 17 will be continually operated to force asteady stream of air'into the forward end of the brake cylinder 7. Nowwhen suflicient pressure is obtained withinthe cylinder 7, the piston-28will be forced rearwardly against the tension of thespring29, causingthe brake block or shoe: 30 to engage the wheel and slow down the car.Any

system of levers, which are suitable for-the purpose, may be employedfor connecting the piston rod 31 and the brake shoe 30.

The valve is held in alinement with the port 9 and is adapted to seatagainst the beveled portions 36 of the walls thereof, as will be clearlyapparent upon reference to Figs. 2 and 3. To hold the valve in itsproper position, I employ a U-shaped frame 37 the ends of which areconnected to the cylinder head on opposite sides of the port 9. A guide38 connects the arms of the frame 37 and is centrally apertured topermit the passage of the valve rod 35, said rod also extending throughan opening 39 in the central portion of the frame. The valve stem 35 isthreaded and carries nuts 40 and 41, the latter of which bears againstanexpansive spiral spring 42 coiled about the stem between the guide 38and the central portion of the frame. The nut 41 is used to adjust thetension of the spring 42 so that the valve 34 may be caused to closewhen any predetermined pressure is created within the cylinder 7. v

A pipe 43 leads from the discharge port 9 along the bottom ofthe car andthen upwardly through the same, as indicatedby the numeral 44, and has avalve 45 connected to its free extremity. A second pipe 46 is connectedto the discharge port 8, extends parallel to the pipe 43 and carries avalve 47 on its extremity.

Having described the construction ofmy improved airbrake system, it nowremains to explain the operation thereof: Then the system is in itsnormal working order, the valves 34 and 45 are open and the valve 47closed. Now supposing, for example, the spring 42 to be adjusted so thevalve 34 will close when a pressure of fifty pounds per square inch hasbeen produced in the cylinder7, said pressure being caused by the pumpwhen the car is running at a speed of seventy-five miles per hour. Thenfor any speed below this rate, the pressure will be below fifty poundsper square inch and the valve 34 will remain open, allowing the air inthe brake cylinder to escape through the pipe 43 and valve 45. When thecar or train reaches a speed of seventy-five miles per hour, the valve34 will close, whereupon the pressure within the cylinder 7 willrapidly'increase, causing the piston 28 to move rearwardly and force thebrake shoe 30 against one of the wheels and so reduce the speed of thevehicle. This same result can be produced by closing the valve 45 andtherefore it will be obvious that the brakes maybe applied irrespectiveof the speed of the car. To release the brake, the valve 47 is opened toallow air to escape from the brake cylinder 7 and then when the valve 45has again been opened, the system is in its normal position and willagain automatically operate to stop the car when a predetermined speedhas been reached.

From the foregoing description taken in connection with the accompanyingdrawings, it will be apparent that I have provided a very simple,etlicient and reliable air brake system and it will be understood thatvariouschanges in the construction, po-

sition and size ofthe various parts may be changed without departingfrom the scope and spirit of the invention as claimed.

Having thus described my invention, I claim 1. In an airbrakesystem, thecombinatio of a brake cylinder, a traction operated pump adapted toforce air into said cylinder, the cylinder being formed with a dischargeport, a valve automatically operated by thepressure within the brakecylinder to close said discharge port, a piston positioned within thebrake cylinder, a brake shoe means operatively connecting the piston andbrake shoe, whereby a movement of the piston in one direction will causethe brake shoe to become operative and valve mechanism operableindependently of said valveto reduce the pressure within the cylinder.

2. In an airbrake system of the character described, the combinationwith a car, of a brake cylinder, a traction operated pump adapted toforce air into said cylinder, the cylinder being formed with a dischargeport, an adjustable valve positioned within the cylinder toautomatically close the discharge port when a fixed pressure is obtainedwithin said cylinder, a piston operable within the brake cylinder, andbrake mechanism operatively connected to said piston.

3. In an airbrake system of the character described, the combinationwith a vehicle, of a brake cylinder, a traction operated pump connectedto said cylinder, the cylinder being formed with a pair of dischargeports, a manually operated valve normally closing one of said ports, asecond valve adapted to automatically close the other discharge portwhen the pressure within the brake cylinder reaches a certain degree, apiston operable within the brake cylinder, and brake mechanism connectedto said piston, the piston operating when the second mentioned valve isclosed to apply the brakes.

4. In an airbrake system of the character described, a brake cylinder,means for forcing air into said cylinder, brake mechanism actuated bycertain predetermined pressure within the brake cylinder, said cylinderbeing formed with a pair of discharge ports, a manually operated valvefor closing one of said ports, a spring pressed valve adapted to closethe other of said ports when a fixed pressure 15 created 1n the brakecylinder, and spring means connected to said second mentioned Valve,whereby the pressure nec-c essary to close said valve may beregulated.

5. In an airbrake system of the character described, a brake cylinder, ameans for forcing air into said cylinder, the cylinder being tormedwitha pair of discharge ports, manually operated means for opening andclosing one of said. ports, a valve positioned within the cylinder toclose the other of said ports when a certain pressure is created withinsaid cylinder, a valve stem secured to said valve, a U-shaped ,framethrough which the valve stem extends, spring means for holding the valvenormally open, adjusting means whereby the tension of said spring meansmaybe varied, brake mechanism operable when said second mentioned valveis closed, and means for manuallyclosing the second mentioned port-s.

In testimony whereof I afliX my signature in presence of two witnesses.

WILLIAM MILLER. Witnesses:

v D. N. WILSON, LAWRENCE M. MCDONNELL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of .Patents,

' Washington, D. G.

